1. Field of the invention
The present invention relates to a vehicle security control apparatus and, more particularly, to a vehicle security control apparatus that performs code comparison through communication with a portable device and, based on the result of comparison, permits or prohibits of use of a vehicle.
2. Description of the Related Art
There are several related-art vehicle security control apparatuses that perform code comparison through communication with a portable device and, based on the result of comparison, either permits or prohibits of use of a vehicle.
JP3-21575, as for example, describes a technology in which when a person operates a manual switch provided in the vehicle, communication between a secret code transmitter carried by the person and a receiver provided in a vehicle is performed. The code signal from the transmitter is compared with a pre-stored code by a code comparator provided in the vehicle. If the comparison signified that the operating person is an authorized user, the running power circuit of the vehicle is turned on and it is possible to unlock the vehicle via the manual switch provided in the vehicle.
However, two potential drawbacks of the related technology is its dependency to signal power source and susceptibility to radio interference. For example, if the normal operation of the code comparison by the code comparator is hindered due to depletion of the power source cell of the secret code transmitter carried by a user, radio interference noises or the like, it becomes impossible to activate the vehicle's power circuit and unlocked the vehicle.